Senior Product Engineer, Treasury (Elixir)

This position is listed on behalf of a partner company, who manages all applications and next steps. Our partner is looking for a Senior Product Engineer, Treasury (Elixir) based in the United States.

Join an innovative engineering team building an AI-powered finance platform that transforms how enterprises manage payments, treasury, and financial operations. As a Senior Product Engineer, you will design and scale the core services behind a treasury platform handling billions in transaction volume. Your work will help enable next-generation financial workflows, including AI agents that initiate corporate expenses, manage travel, and use payment cards. Working closely with founders and a small, senior team across engineering, product, treasury, and data/AI, you will shape product direction and technical architecture. This hands-on role combines deep Elixir expertise with end-to-end product ownership, from defining requirements and building interfaces to operating reliable production systems. The position is fully remote for US-based candidates working Eastern Time hours, with significant autonomy and opportunities to influence the future of financial technology.

Accountabilities:
As a Senior Product Engineer, you will take ownership of critical treasury product capabilities, building reliable backend services and complete user-facing features. You will contribute to technical strategy, establish strong engineering practices, and help deliver resilient systems that support increasingly sophisticated financial workflows.

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Design, build, deploy, and operate Elixir and Phoenix services, including APIs, data pipelines, and asynchronous processing systems.

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Own product features throughout the entire software development lifecycle, from problem discovery and requirements definition to backend implementation, frontend delivery, and production operations.

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Develop and scale core treasury services that support high-volume financial transactions and emerging AI-driven spending workflows.

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Build and improve infrastructure that enables AI agents to initiate corporate expenses and travel, as well as create and use payment cards.

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Prioritize reliability across critical Tier 0 and Tier 1 systems through robust observability, monitoring, and operational practices.

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Collaborate directly with company founders and senior colleagues across treasury, product, engineering, and data/AI to shape product direction and technical decisions.

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Use AI-assisted development tools, particularly Claude Code, to improve engineering productivity and support high-quality implementation.

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Help establish and refine architectural standards, engineering workflows, development practices, and code review processes.

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Contribute to a collaborative engineering culture focused on end-to-end ownership, maintainability, and dependable production systems.

Requirements:

The ideal candidate is an experienced product-minded engineer with strong production experience in Elixir and Phoenix, a solid understanding of distributed systems, and the ability to deliver complete features independently. You should combine technical depth with clear communication, sound product judgment, and practical experience using AI-assisted development tools.

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Be based in the United States and able to work Eastern Time hours in close collaboration with the treasury team.

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Have at least 5 years of professional software engineering experience.

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Demonstrate strong hands-on experience developing and operating production applications with Elixir and Phoenix.

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Be comfortable owning features end-to-end, from product framing and requirements through backend services, frontend implementation, and production support.

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Have a solid understanding of distributed systems, concurrency, and asynchronous processing.

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Possess strong PostgreSQL skills and practical experience with cloud infrastructure, Kubernetes, and CI/CD pipelines.

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Demonstrate fluent, day-to-day use of AI coding tools, particularly Claude Code, in real software development workflows.

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Communicate clearly with both technical and non-technical stakeholders.

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Have fluent English communication skills.

Nice-to-have qualifications:

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Experience with Python or other backend programming languages.

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Background in payments, treasury, fintech, or related financial technology domains.

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Familiarity with event-driven architectures, message queues, and workflow orchestration.

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Exposure to AI- or machine learning-powered products.

Benefits:

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Competitive compensation: Salary package designed to reflect experience and expertise.

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Meaningful equity: Opportunity to participate in the company's growth and success.

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AI tooling budget: Extensive resources for AI-assisted development and engineering productivity.

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Generous paid time off: Support for rest, personal commitments, and work-life balance.

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Remote-first flexibility: Fully remote work with a flexible schedule, aligned with Eastern Time collaboration.

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Health and wellness: Comprehensive health coverage and wellness benefits.

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Autonomy and ownership: Direct influence over product direction, architecture, and engineering decisions.

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Innovative technical environment: Opportunity to build advanced payment and treasury infrastructure, including AI-driven financial workflows.

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Inclusive culture: A commitment to diversity of thought, culture, and background, with equal employment opportunities.